JP2017506096A - Alternative placement of temperature sensors on bipolar electrodes - Google Patents

Abstract

A medical device for tissue ablation includes a catheter shaft, an expandable member disposed on or coupled to the catheter shaft, and a plurality of elongated electrode assemblies each configured as a flexible circuit. Is provided. The expandable member is configured to change between an unexpanded configuration and an expanded configuration. The plurality of electrode assemblies are disposed on the outer surface of the expandable member. Each of the plurality of electrode assemblies includes a temperature sensor aligned with two or more electrodes.

Description

  The present disclosure relates to medical devices and methods of manufacturing medical devices. In particular, the present disclosure relates to a tissue ablation medical device.

  A variety of internal medical devices have been developed for medical applications such as, for example, intravascular use. Some of these devices include guidewires, catheters, and the like. These instruments are manufactured by any one of a variety of different manufacturing methods and used by any one of a variety of methods.

  Each of the known medical devices and methods has certain advantages and disadvantages. In addition to alternative methods for manufacturing and using medical devices, there is a continuing need to provide alternative medical devices.

  A medical device for tissue ablation includes a catheter shaft and an expandable balloon disposed on the catheter shaft. The balloon can change between an unexpanded configuration and an expanded configuration. The medical device includes a plurality of elongated electrode assemblies each configured as a flexible circuit. Each of the plurality of electrode assemblies includes at least a first and second spaced apart plurality of electrodes, the plurality of electrode assemblies being disposed on an outer surface of the balloon. Each of the plurality of electrode assemblies includes one or more temperature sensors aligned with two or more electrodes in the array.

  A medical device for tissue ablation includes a catheter shaft, an expandable member coupled to the catheter shaft, and a plurality of elongated electrode assemblies each configured as a flexible circuit. The expandable member can change between an unexpanded configuration and an expanded configuration. The plurality of electrode assemblies are disposed on the outer surface of the expandable member, and each of the plurality of electrode assemblies includes at least one temperature sensor positioned under the at least one electrode.

  A medical device for tissue ablation in a body passage includes a catheter shaft having a longitudinal axis, an expandable member coupled to the catheter shaft, and a plurality of elongated electrode assemblies each configured as a flexible circuit. Is provided. The expandable member can vary between an unexpanded configuration and an expanded configuration, and the plurality of electrode assemblies are joined to the outer surface of the expandable member. Each of the plurality of electrode assemblies includes a plurality of active electrodes, a plurality of outer electrodes, and one or more temperature sensors. The temperature sensor is linearly arranged on the plurality of outer electrodes.

  The means for solving the above-mentioned problems of some embodiments are not intended to disclose each or every implementation of the embodiments presented in this disclosure. The drawings and detailed description to be described below more particularly exemplify these embodiments.

1 is a schematic diagram illustrating a tissue ablation instrument according to an example. FIG. 1 is a partial plan view of an electrode assembly according to the prior art. FIG. 1 is a partial plan view of an electrode assembly according to the prior art. FIG. 1 is a partial plan view of an electrode assembly according to the prior art. FIG. FIG. 2 is a partial plan view illustrating an exemplary electrode assembly. FIG. 2 is a partial plan view illustrating an exemplary electrode assembly. FIG. 2 is a plan view illustrating an exemplary electrode assembly. FIG. 2 is a plan view illustrating an exemplary electrode assembly. FIG. 3 is a perspective view of an exemplary expandable member of a tissue ablation instrument. FIG. 2 is a partial plan view illustrating an exemplary electrode assembly. The fragmentary sectional view of FIG. FIG. 2 is a partial plan view illustrating an exemplary electrode assembly. FIG. 2 is a partial plan view illustrating an exemplary electrode assembly. FIG. 2 is a partial plan view illustrating an exemplary electrode assembly. FIG. 2 is a partial plan view illustrating an exemplary electrode assembly. FIG. 2 is a partial plan view illustrating an exemplary electrode assembly. FIG. 3 is a partial cross-sectional view illustrating an exemplary electrode assembly. 15A is a temperature profile at section AA of the assembly of FIG. 14, FIG. 15B is a temperature profile at section BB of the assembly of FIG. 14, and FIG. 15C is a section C— of the assembly of FIG. Temperature profile at C. 2 is a graphical representation showing temperature profiles at various distances from the center of an exemplary electrode.

The present disclosure will be more fully understood in view of the following detailed description with reference to the accompanying drawings.
While the present disclosure is flexible in various modifications and alternative forms, specific examples thereof are illustrated in the drawings and will be described in detail later. However, it can be said that the present invention is not intended to be limited to a given embodiment. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure.

  The specification should be read with reference to the drawings, wherein like reference numerals indicate like elements throughout the several views. The drawings are not necessarily to scale. The detailed description and drawings are intended to be illustrative only and are not intended to limit the claimed invention. Those skilled in the art will recognize that the various elements disclosed and / or illustrated may be provided in various combinations and configurations without departing from the scope of the present disclosure. The detailed description and drawings illustrate embodiments of the claimed invention.

With respect to the terms defined below, these definitions shall apply unless a different definition is given in the claims or elsewhere in this specification.
All numbers are assumed to be modified by the term “about”, whether explicitly indicated or not. The term “about” indicates in the numerical context a numerical range that one of ordinary skill in the art would appreciate (ie, having the same function or result) as would normally be described. In many instances, the term “about” includes numbers that are rounded to the nearest significant figure. Other uses of the term “about” (ie, in a non-numeric context) are understood from the context of the specification, unless otherwise specified, and are in its usual customary manner to be consistent with the context of the specification. It is assumed to have a definition.

The recitation of numerical ranges by endpoints includes all numbers within that range including endpoints (eg, 1 to 5 is 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5). Including).
As used herein and in the appended claims, the singular “a”, “an”, and “the” include plural referents unless the content clearly dictates otherwise. As used herein and in the appended claims, the term “or” is generally used in its sense including “and / or” unless the content clearly dictates otherwise.

  References herein to “embodiments”, “some embodiments”, “another example”, etc., include one or more disclosed embodiments including certain features, structures, or characteristics. However, not all embodiments necessarily include specific features, structures, or characteristics. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a given feature, structure, or characteristic is described with respect to one embodiment, such feature, structure, or characteristic is clearly stated to the contrary, whether or not explicitly disclosed. Unless otherwise stated, it is within the knowledge of those skilled in the art to obtain other examples. That is, the various individual elements disclosed below may be made or disclosed in other additional embodiments, as will be appreciated by those skilled in the art, even if not explicitly shown in a particular combination. It is contemplated that they can be combined with each other or arranged with respect to each other to supplement and / or develop one or more embodiments.

  The predetermined treatment is aimed at tissue ablation. In some examples, tissue ablation includes temporary or permanent interruption or correction of selected neural function. In some embodiments, the nerve is a sympathetic nerve. One example of treatment is renal nerve ablation, which is usually used to treat hypertension, congestive heart failure, diabetes, or other symptoms affected by high blood pressure or salt retention, or related symptoms. used. The kidney produces a sensitive response, which increases the undesirable retention of water and / or sodium. The result of the sensitive response is, for example, an increase in blood pressure. Ablation of some of the nerves that extend to the kidney (eg, adjacent to or located along the renal artery) reduces or eliminates this sensitive response, and is therefore associated with an undesirable Symptoms are correspondingly reduced (eg, reduction in blood pressure).

  Some embodiments of the present disclosure relate to a power generation and control device for the treatment of normal purpose tissue to obtain a therapeutic effect. In some embodiments, the tissue of interest is a tissue that includes or is near a nerve. In another example, the tissue of interest is a sympathetic nerve, including, for example, a sympathetic nerve placed adjacent to a blood vessel. In yet another example, the tissue of interest is luminal tissue, which further includes diseased tissue such as found in major diseases.

  In some embodiments of the present disclosure, the ability to transmit energy during the intended dose is used in neural tissue to obtain a beneficial biological response. For example, it is well known that chronic pain, urological dysfunction, hypertension, and various other persistent symptoms are affected by nerve tissue surgery. For example, it is well known that chronic hypertension that is not responsive to drugs can be ameliorated or eliminated by disabling excessive nerve activity near the renal arteries. It is further well known that neural tissue usually does not have regenerative properties. Therefore, it is possible to effectively influence excessive nerve activity by splitting the transmission path of nerve tissue. It is particularly effective to avoid damage to nearby nerves and organ tissues when disrupting the nerve transmission pathway. The ability to direct and control energy dosage is suitable for the treatment of neural tissue. Regardless of the heating energy dose or the ablation energy dose, precise control of energy transport as described and disclosed herein is directed to the neural tissue. Furthermore, the directed application of energy is sufficient to target the nerve without requiring precise contact, as required when using conventional ablation probes. For example, eccentric heating is applied at a temperature high enough to degenerate neural tissue without causing ablation and requiring penetration of luminal tissue. However, it is further desirable to construct the energy transport surface of the present disclosure that transports ablation energy similar to an ablation probe that penetrates tissue and has the precise energy dosage controlled by the power supply control and generation device.

  In some embodiments, the efficacy of denervation therapy is assessed by measurement before, during, and / or after treatment to adjust one or more parameters of the therapy for a particular patient or additional Identify the need for treatment. For example, does the denervation system include the ability to assess whether treatment has reduced or reduced the nerve activity of the target tissue or nearby tissue, and can this provide feedback to adjust treatment parameters? The need for additional treatment is indicated.

  Many of the devices and methods disclosed herein are discussed with respect to renal nerve ablation and / or adjustment. However, it is contemplated that the devices and methods may be used in other treatment locations and / or applications. Neural adjustments and / or other tissue adjustments including heating, activation, occlusion, division, or ablation are desirable in, but not limited to, blood vessels, urine vessels, or other tissues via trocar and cannula access Is not to be done. For example, the devices and methods disclosed herein include proliferative tissue ablation, cardiac ablation, pain treatment, pulmonary vein isolation, pulmonary vein ablation, tumor ablation, treatment for benign prostatic hyperplasia, nerve stimulation, block or ablation, muscle activity It is applicable to adjustment, high heat, or other temperature increase of the tissue. The disclosed methods and devices are applicable to any relevant medical procedure, including both human and non-human patients. The term “modulation” refers to ablation and other techniques that alter the function of affected nerves and other tissues.

  FIG. 1 is a schematic diagram illustrating an exemplary sympathetic ablation system 100. System 100 includes a sympathetic ablation instrument 120. The sympathetic ablation instrument 120 is used to remove nerves (eg, renal nerves) placed adjacent to the kidney K (eg, renal nerves placed around the renal artery RA). In use, sympathetic ablation instrument 120 is advanced through a blood vessel such as aorta A to a location within renal artery RA. This includes advancing the sympathetic ablation instrument 120 through the guide sheath or catheter 14. When positioned as desired, the sympathetic ablation instrument 120 is activated to activate one or more electrodes (not shown). Activation includes operatively coupling the sympathetic ablation instrument 120 to a controller 110 that includes an RF generator so as to provide the desired activation energy to the electrodes. For example, the sympathetic ablation instrument 120 includes a wire or conductive member 18, the first connector 20 can be connected to the second connector 22 on the control device 110, and / or the wire 24 is connected to the control device. 110. In at least some embodiments, the controller 110 may be configured with an appropriate electrical device to activate one or more sensors located at or near the distal end of the sympathetic ablation instrument 120. It may also be used to supply or receive energy and / or signals. When properly activated, one or more electrodes can ablate tissue (eg, sympathetic nerves), as described below, and one or more sensors sense desired physical and / or biological parameters. Used to do.

  Sympathetic ablation instrument 120 includes an elongate tubular member or catheter shaft 122. In some embodiments, the elongate tubular member or catheter shaft 122 is configured to be slidably advanced over a guidewire or other elongate medical device to a target site. In some embodiments, the elongate tubular member or catheter shaft 122 is configured to be slidably advanced within the guide sheath or catheter 14 to a target site. In some embodiments, the elongate tubular member or catheter shaft 122 may be configured to be advanced over the guidewire into the guide sheath or catheter 14, or a combination thereof, to the target site. Good. The expandable member 130 is disposed in the distal region of the elongate tubular member or catheter shaft 122, on the distal region, around the distal region, or near the distal region. . In some embodiments, the expandable member 130 is a compliant or non-compliant balloon. In some embodiments, the expandable member 130 can change between an unexpanded configuration and an expanded configuration.

  The use of a medical device that includes a balloon with one or more electrode assemblies to be coupled is desirable, eg, as disclosed herein. However, in some instances, the electrode assembly is relatively rigid and / or includes bulky materials or elements. Thus, when the balloon is deflated according to the treatment procedure, the electrode assembly tends to become flat and / or unfolded. When so configured, the one or more electrode assemblies, and / or elements or edges thereof, guide the medical device when stored proximally (eg, including the attached electrode assembly) within the guide catheter. • It may get caught on the edge of the catheter. A medical device that includes structural elements that reduce the size of the electrode assembly, the electrode assembly and other structures of the medical device, for example, the likelihood of "snipping" the end of the guide catheter upon storage within the guide catheter. Disclosed, thereby reducing the retracting force.

  The electrode assemblies are provided on an expandable member, each assembly including one or more of each of an outer electrode 10, a positive electrode 12, and a temperature sensor or thermistor 26. Some prior art electrode pair designs consist of an electrode pad 70 having a plurality of outer electrodes 10 spaced a few millimeters away from a plurality of positive electrodes 12, as shown in FIG. Is disposed between the electrodes. Thus, when individual electrodes are activated, accurate temperature detection can be performed, thereby forming a consistent affected area. Each individual electrode pair is activated individually to treat zigzag around the blood vessel. As shown in FIG. 2B, when the electrode assembly is placed on the balloon catheter, the electrode assembly is wired to be individually activated around each thermistor.

  For other applications, a more complete and peripheral treatment is desirable. In such applications, the electrode pairs are configured to start within the pair indicated by arrow 50 and between the pair indicated by arrow 60. See FIG. In this scenario, the pair between the electrodes does not have a thermistor for monitoring temperature during activation.

  As shown in FIG. 4, an additional thermistor 26 is placed between the electrode pads 70 to monitor the temperature of the pair between the electrodes. However, this arrangement requires that the number of thermistors be doubled, which requires additional surface area on the balloon, increases the rigidity and profile of the balloon, and completes the circuit for the additional thermistor. Additional electrical connections are required to achieve this. The thermistor is the largest element of the electrode assembly. For example, the thermistor is 0.02 inches (0.0508 centimeters) by 0.04 inches (0.1016 centimeters) and 0.006 inches (0.01524 centimeters) thick. When placed between the electrodes, the thermistor increases circuit profile and circuit area / mass. This structure makes the expandable member more difficult to fold and requires larger catheters and sheaths.

  In some embodiments, the temperature sensor is placed off-center on the bipolar electrode structure to reduce the flexible circuit profile and improve the foldability of the balloon so that the balloon has a smaller sheath. And can pass through the catheter. By moving the temperature sensor off center or along the electrode, the expandable member can be folded along the center of the two rows of electrodes without damaging the temperature sensor. When the balloon is retracted, the temperature sensor is withdrawn along with the backbone of the flexible circuit where the electrodes are placed. The middle part between the two rows of electrodes is easily folded. This structure allows the instrument to be inserted and retracted into a smaller sheath or catheter.

  FIG. 5 shows an exemplary temperature sensor arrangement. Thus, the temperature of both the pair of electrodes and the pair of electrodes to be activated can be sufficiently monitored without increasing the number of temperature sensors. As shown in FIG. 5, a temperature sensor 226 such as a thermistor is disposed under the outer electrode 210. A layer of insulating material such as polyimide is disposed between the outer electrode 210 and the temperature sensor 226. In this arrangement, as shown in FIG. 6A, the temperature sensors 226 monitor the temperature in the activated electrode pair 50 and in the activated electrode pair 60, respectively. The starting frequency and sequence is controlled by the generator hardware and software, which optimizes temperature accuracy and reduces the amount of cross talk between electrode activation and temperature sensing. In some embodiments, a longer length balloon is desirable. The electrode assembly 140 is extended and an additional electrode 222, including both the outer electrode 210 and the active positive electrode 212, and a temperature sensor 226 are added to the array extending along the length of the electrode, and the temperature along the entire length. To monitor. See FIG. 6B. The electrodes are arranged in parallel to each other or at an angle to each other and spaced apart from each other. In some embodiments, the region 145 of the electrode assembly between the array of electrodes 210 and 212 lacks circuitry. This area 145 lacking circuitry assists in folding the electrode assembly.

  Each electrode assembly 140 includes a plurality of individual conductive traces stacked on the base layer 202. The plurality of individual conductive traces include an outer electrode trace 210, an active or positive electrode trace 212, and a temperature sensor trace 214. Outer electrode trace 210 includes an elongated outer electrode support 216 and active electrode trace 212 includes an elongated active electrode support 217. In order to obtain the desired amount of flexibility, the electrode supports 216 and 217 are narrower in width at their proximal ends, but this is not necessary. Typically, the curvature of the trace where necking is indicated is optimized so that the balloon recovery force is reduced and the possibility of a stagnation exhibited by a sharper profile is reduced. The shape and position of the traces are also optimized to provide overall dimensional stability to the electrode assembly 140, thereby preventing distortion during deployment and use.

  As shown in FIG. 6B, the outer electrode trace 210 and the active electrode trace 212 each include a plurality of electrodes 222. However, in some embodiments, at least one electrode is provided on each electrode trace and used more or less. For example, in some embodiments, three electrodes are provided on each electrode trace. See FIGS. 11-13. Alternatively, as shown in FIGS. 7 and 8, up to 35 or more electrodes may be provided on each electrode trace. The plurality of electrodes 222 project upward and / or extend through the insulating layer 206.

  In some embodiments, the plurality of electrodes 222 are attached to the elongated active electrode support 217 and / or attached to at least one active electrode and the elongated outer electrode support 216 that are electrically connected. And / or includes at least one outer electrode that is electrically connected. In some embodiments, the plurality of electrodes 222 are attached to and / or electrically connected to the elongate outer electrode support 216, thereby forming a plurality of outer electrodes and / or elongate. The active electrode support 217 is attached and / or electrically connected to form a plurality of active electrodes. In some embodiments, the plurality of electrodes 222 has a thickness of about 0.030 mm to about 0.070 mm. In some embodiments, the plurality of electrodes 222 is about 0.051 mm thick. In some embodiments, the plurality of electrodes 222 extends from about 0.020 mm to about 0.050 mm above the insulating layer 206. In some embodiments, the plurality of electrodes 222 extend about 0.038 mm over the insulating layer 206. In addition, each electrode has rounded corners to reduce the tendency to catch on other instruments and / or tissue. Although the above description of multiple electrodes, and their associated traces, has been disclosed in the context of a bipolar electrode assembly, those skilled in the art will recognize that the same electrode assembly functions in a monopolar mode as well. . For example, as one non-limiting example, the plurality of electrodes associated with the active electrode trace 212 is used as a monopolar electrode, and the outer electrode trace 210 is separated during activation of those electrodes.

  In some embodiments, the temperature sensor 226 has a length of about 0.100 mm to about 2.000 mm and a width of about 0.100 mm to about 0.800 mm. In some embodiments, the temperature sensor 226 has a length of about 1.000 mm and a width of about 0.500 mm. In another example, the temperature sensor may have a length of about 0.2 mm and a width of 0.01 mm. Other sizes and / or dimensions are possible.

  In some embodiments, the electrodes tilt around the balloon at a slight angle to form a helical structure around the balloon, which assists in deflating the balloon after treatment. . For example, as shown in FIG. 7, the plurality of electrode assemblies 140 are arranged at an angle on an expandable member 130 shown in an expanded state. The electrode assembly 140 is configured such that the energy applied by the electrode assembly provides a treatment that overlaps or does not overlap. The treatment applied by the electrode assembly 140 may be continuous or discontinuous circumferentially along the longitudinal axis LL. The energy applied by an electrode assembly such as electrode assembly 140 shown in FIG. 7 overlaps at least to some extent in the longitudinal direction, circumferentially and / or otherwise. The electrode assembly 140 shown in FIGS. 7 and 8 includes a rectangular base layer 202. This is not intended to be limiting. Other shapes are possible. In addition, the electrode assembly 140 includes a plurality of openings extending therethrough to provide additional flexibility, with portions of the assembly including rounded or curved corners, transitions, and other portions. . In some instances, the openings and rounded / curved elements increase the assembly's resistance to delamination from the expandable member 130. Delamination occurs in some instances when the expandable member 130 is repeatedly expanded and folded as required, for example, during treatment of multiple sites (this is further from the protective sheath). Inevitably involves deployment and storage within a protective sheath).

  An example electrode assembly 140 is shown in FIG. As shown in FIG. 8, each electrode assembly 140 includes one or more temperature sensors 226 on the sensor trace 214 and a plurality of electrodes 222, some disposed on the outer array trace 210, Are placed on an active or positive array or trace 212. Sensor trace 214 is centrally disposed on electrode assembly 140. In other examples, sensor trace 214 is positioned adjacent to one of the arrays or traces 210 and 212. Each electrode assembly 140 includes a proximal tail 180 that includes a narrow region extending from the proximal end of the expandable member 130 along the catheter shaft 122 to the proximal end of the catheter shaft 122.

  In some embodiments, the temperature sensor 226 is a thermistor. As shown in FIG. 9, the temperature sensor 226 is disposed on the non-tissue contact side (that is, the bottom side) of the electrode assembly 140. Thus, when incorporated into the ablation instrument 120, the temperature sensor 226 is captured between the electrode assembly 140 and the expandable member 130. This is advantageous because surface mount electrical elements such as thermistors usually have sharp edges and corners, which can trap tissue and cause problems during balloon deployment and / or storage. Since solder is usually not biocompatible, this arrangement keeps the soldered connections out of contact with blood.

  Depending on the size and / or thickness of the electrode assembly 140 at the temperature sensor 226, a protrusion is formed that extends outwardly from the outer surface of the expandable member 130. In accordance with the treatment procedure, as further discussed herein, the expandable member 130 is folded into a collapsed transport configuration and the ablation instrument 120 is stored within the guide sheath or catheter 14. One or more substantial protrusions may be more difficult to retract into the guide sheath or catheter 14 and / or require a larger diameter guide sheath or catheter 14, although it is desirable otherwise. In addition, the one or more protrusions negatively affect the folding characteristics of the expandable member 130 during both transportation and storage.

  FIG. 9 shows an example electrode assembly 140 and a partial plan view of a cross section thereof. In the cross-sectional view of FIG. 9, the bottom of the figure is the portion of electrode assembly 140 that faces, contacts, and / or attaches and / or joins the outer surface of expandable member 130 directly. In some embodiments, the insulating base layer 202 provides the base of the electrode assembly 140. The base layer 202 is composed of a polymer such as polyimide, but other materials are also contemplated. In some embodiments, the base layer 202 has a thickness of about 0.010 mm to about 0.020 mm. In some embodiments, the base layer 202 is about 0.015 mm thick. Other suitable thicknesses are also contemplated. For reference, the base layer 202 directly faces the outer surface of the expandable member 130 and forms the majority of the bottom side of the electrode assembly 140 that is in contact with and / or attached and / or joined. Also good.

  The first conductive layer 204 includes a plurality of individual conductive traces stacked on the base layer 202. In some embodiments, the plurality of individual conductive traces are separated transversely by a non-conductive material. The plurality of individual conductive traces of conductive layer 204 include, for example, a layer of electrodeposited copper or rolled annealed copper. Other suitable conductive materials are also conceivable. In some embodiments, the conductive layer 204 and / or the plurality of individual conductive traces have a thickness of about 0.010 mm to about 0.030 mm. In some embodiments, the conductive layer 204 and / or the plurality of individual conductive traces are about 0.018 mm thick. Other suitable thicknesses are also contemplated. The first conductive layer 204 is etched to form a positive ground connection for the temperature sensor 226. The temperature sensor 226 is disposed so as to cover the first conductive layer.

  The second conductive layer 304 is disposed so as to cover the base layer 202, and the insulating layer 206 is laminated on the top of the second conductive layer 304 discontinuously or continuously. As a result, the second conductive layer 304 is liquid-tightly sealed between the base layer 202 and the insulating layer 206. That is, the insulating layer 206 forms the top side or surface of the electrode assembly 140 that does not face the outer surface of the expandable member 130. The relationship between the base layer 202, the first conductive layer 204, the second conductive layer 304, and the insulating layer 206 is exemplary, and other structures are possible. As with the base layer 202, the insulating layer 206 is made of a polymer such as polyimide, although other materials are conceivable. In some embodiments, the insulating layer 206 is about 0.010 mm thick to about 0.020 mm thick. In some embodiments, the insulating layer 206 is about 0.013 mm thick. Other suitable thicknesses are also contemplated. In some embodiments, the insulating layer 206 is a complete or partial polymer coating such as PTFE or silicone. Other materials are also conceivable.

  The electrode assembly 140 is configured as a flexible circuit having a plurality of layers. Such layers are continuous or non-adjacent (ie, composed of discrete parts). Electrode assembly 140 is a multi-layer structure comprising an electrode 222 on the upper surface (spaced from the expandable member) and a temperature sensor such as temperature sensor 226 on the lower surface (relative to the expandable member). . The electrode assembly 140 includes one or more polymer layers and one or more layers of conductive material. As shown in the cross section of FIG. 9, the electrode assembly 140 includes two polymer layers 202 and 206, two conductive layers 204 and 304, a temperature sensor 226, and an electrode 222. The polymer layer and conductive layer are laminated sheets of polymer layers 202 and 206 that are bonded to the conductive layers 204 and 304 with an adhesive. In some embodiments, two such sheets are joined together with an adhesive layer 205. As shown in FIG. 9, the two polymer / conductive sheets are integrally joined to the polymer side with respect to the conductive side, so that the cross section begins at the upper surface (separate from the expandable member). Thus, a structure of alternating polymer 206, conductive portion 304, adhesive 205, polymer 202, and conductive portion 204 is obtained.

  The second conductive layer 304 is etched to form a trace for the ground and positive electrode 222 pair. A via is formed to connect the electrode ground trace of the second conductive layer 304 to the temperature sensor 226 ground trace of the first conductive layer 204. The temperature sensor 226 is soldered on the first conductive layer 204. The insulating layer 206 is shaved so as to form a recess 208, and is gold-plated to form a gold electrode 222.

  In another example shown in FIG. 10A, one of the outer electrode recesses is removed and the temperature sensor 226 is located in the region where the recess was once. The recess 208 is oriented in any direction. The first conductive layer 204 is configured to share the ground trace 210 with the temperature sensor 226, and a new trace is formed for the positive connection of the temperature sensor. In the longer electrodes that require more temperature sensors, the temperature sensors are placed along the ground trace 210 and wired in parallel to each other, as shown in FIG. 10B. Alternatively, if multiple temperature sensors are used, the temperature sensors may be individually wired (not shown).

  In some embodiments, the one or more electrode assemblies 140 are disposed along or form a crease line and the expandable member 130 contracts along the crease line. It will be folded later. In some embodiments, the predetermined crease line assists in refolding the expandable member 130. In some embodiments, the one or more electrode assemblies 140 are substantially linear and are along the longitudinal axis LL along the entire length of the expandable member 130 or at an angle to the axis LL. Extend. In some embodiments, the electrode assembly extends parallel to the longitudinal axis of the proximal region and is subsequently bent into an angular orientation in the distal region (not shown). The one or more electrode assemblies 140 cause the balloon to fold along the line of the one or more electrode assemblies 140, thereby reducing the storage force required to store the ablation instrument 120 within the guide sheath or catheter 14. Accordingly, a guide sheath having a smaller diameter can be used. For example, a 6Fr or 7Fr guide catheter 14 is used, which can be beneficial in certain procedures where an 8Fr guide catheter has been previously used (eg, kidney treatment). The one or more electrode assemblies 140 may further reduce shear forces or improve balloon refolding performance, thereby reducing separation of the one or more electrode assemblies 140 from the expandable member 130.

  As shown in FIG. 8, in some embodiments, the electrode assembly 140 includes a single row or array of positive electrodes 212 and a single row or array of outer electrodes 210. As shown in FIGS. 11A and 11B, in another example, electrode assemblies 340 and 440 include electrode pads 308 and 336 and 408 and 436 spaced longitudinally. Moving proximally from the distal electrode pads 308 and 408, the connected base layer 202, conductive layer 304, and insulating layer 206 have reduced side widths leading to the intermediate tails 328 and 428. Continuing to move proximally from the middle tails 328 and 428, the connected base layer 202, conductive layer 304, and insulating layer 206 increase in lateral width to form proximal electrode pads 336 and 436. Proximal electrode pads 336 and 436 are configured similarly to distal electrode pads 308 and 408. However, as shown, the proximal electrode pads 336 and 436 are offset laterally from the distal electrode pads 308 and 408 with respect to a central longitudinal axis extending along the electrode assemblies 340 and 440.

  From the proximal electrode pads 336 and 436, the coupled base layer 202, conductive layer 304, and insulating layer 206 are reduced in lateral width to form proximal tails 338 and 438. Proximal tails 338 and 438 include connectors (not shown) that can be coupled to one or more sub-wiring harnesses and / or connectors and ultimately to controller 110. Each of these lines extends along a corresponding axis parallel to the central axis of electrode assemblies 340 and 440. Electrode assemblies 340 and 440 have a symmetrical or asymmetrical arrangement of distal electrode pads 308 and 408 and proximal electrode pads 336 and 436 with respect to the central axis of electrode assemblies 340 and 440. Further, the outer electrodes 210 of both electrode pads are generally arranged along the central axis in addition to the ground wire. It has been found that this arrangement provides a predetermined effect. For example, by sharing substantially the same ground trace, the width of the proximal tail is about twice that of the middle tail, compared to about twice when each electrode pad has a separate ground wire. Only about 1.5 times. Accordingly, the proximal tails 338 and 438 are narrower than the two middle tails 328 and 428 located side by side.

  FIG. 11A shows an electrode assembly 340 comprising linear rows of positive electrodes 212 and outer electrodes 210, with the substrate material comprising the base layer 202 extending between these rows. FIG. 11B shows a similar electrode assembly 440 comprising substrate material cut between linear rows of electrodes 212 and 210. By removing the substrate material between the rows of electrodes, the mass of the circuit that needs to be folded is reduced. When placed on a balloon, electrode assembly 440 exhibits enhanced foldability as compared to electrode assembly 340. The reason is that the absence of a substrate between the linear rows of electrodes makes it easier to fold between the rows of electrodes and the temperature sensor 226 to be folded together with the outer electrode 210. With this structure, the instrument can be inserted or retracted through a smaller sheath or catheter. However, as shown in FIG. 11A, even when a base layer 202 is provided between the electrode rows, by moving the temperature sensor 226 away from the center and onto the electrode rows, FIG. Foldability is enhanced over the prior art electrode assembly shown in FIG. 2B. The electrode assemblies 340 and 440 shown in FIGS. 11A and 11B further illustrate a temperature sensor 226 disposed along the most proximal outer electrode 210 and proximal to the outer electrode 210. This structure provides two linear rows of electrodes and a temperature sensor, which assists in folding the electrode assembly along a line between the rows of electrodes.

  In some embodiments, the temperature sensor 226 is a sputtered thermocouple (eg, type T structure: copper / constantan). In the embodiment shown in FIGS. 12A and 12B, the temperature sensor is a thermocouple 426 with a connection near the middle electrode on the ground trace 210. The intermediate electrode has less change due to the addition of the balloon and has better correlation or error with respect to the center position according to the prior art. In some embodiments, the thermocouple includes separate layers of copper and constantan. The thermocouple is formed by a through hole between the two layers and filled with solder. Thereby, a through-hole becomes a thermocouple connection part. Similar to FIGS. 11A and 11B, FIG. 12A shows an electrode assembly 440 having a substrate or base layer 402 disposed between a ground trace 210 and a positive trace 212, and FIG. 12B shows an array of positive and negative electrodes on the substrate. The electrode assembly 540 is shown removed between.

  As shown in FIGS. 13A and 13B, the thermocouple coupling is located on or near the proximal outer electrode. The connecting portion by heat is formed of copper and constantan (T type) instead of gold and constantan. However, the connection is in the vicinity of the copper layer so that the connection can measure the exact temperature of the heating element. Thermocouples generate a differential voltage at the junction based on the temperature at the junction of two different metals, as is well known in the art. In some embodiments, an isothermal connection is formed at the proximal end of the electrode assembly 140 and is spaced and thermally isolated from the one or more electrode pads and / or electrodes. The In some embodiments, temperature sensor 226 is formed as a separate trace of electrodeposited copper in conductive layer 204. In some embodiments, the distal end of sensor trace 214, and in some cases, the entire sensor trace 214 may be, for example, constantan (ie, copper-nickel alloy), nickel-chromium, or other It is formed from a suitable conductive material.

  FIG. 13A shows another example electrode assembly 640 having parallel columns of outer electrodes 210 and positive electrodes 212 on a substrate or base layer 502. The temperature sensor 526 is a thermocouple including a coupling portion at the proximal end of the outermost electrode 210 on the most proximal side. FIG. 13B shows a similar electrode assembly 740 with a portion of the base layer 502 removed between the outer electrode 210 and positive electrode 212 rows.

  Exemplary instruments have a very uniform temperature profile on the balloon and within the tissue during RF transmission due to their balloon structure and bipolar energy transfer. FIG. 14 is a cross-sectional view illustrating a simplified model electrode assembly 840 comprising an electrode 822, a conductive layer 804, and a base layer or substrate 802. FIGS. 15A-15C show the thermal profiles of various surfaces heated for 30 seconds. FIG. 15A shows the surface of the polyimide base layer 802 in section AA of FIG. FIG. 15B shows the bonding surface between the copper conductive layer 804 and the polyimide base layer 802 in section BB of FIG. FIG. 15C shows the outer diameter of the balloon in section CC in FIG. As can be seen by comparing FIGS. 15A-15C, the temperature profile is substantially constant across the cross section of the electrode assembly 840. The temperature at the center of the balloon 1501 approximates the temperature of the electrode 1502. Because of this consistency, the temperature at the center of the balloon 1501 further approximates the temperature of the edge of the electrode assembly 1502 and is well related to this temperature.

  FIG. 16 shows the temperature at the center of electrode pair 1601 and the temperature at various distances from the center. As shown, the temperature is substantially constant from the center of the electrode pair to the edge of the electrode row. Measuring the temperature in the vicinity of the electrodes has been found to be appropriate for temperature adjustment instead of the central temperature measurement, and to maintain consistency of the affected area.

  In use, the ablation instrument 120 is advanced through a blood vessel or body passageway to a location adjacent to the tissue of interest (eg, within the renal artery), in some cases with the aid of a transport sheath or catheter 14. In some embodiments, the tissue of interest is one or more sympathetic nerves that are placed around a blood vessel. In some embodiments, the controller 110 is operatively coupled to the ablation instrument 120. The ablation instrument 120 is inserted into a blood vessel or body passageway such that the expandable member 130 (having a plurality of electrode assemblies 300) is positioned adjacent to the tissue of interest that requires treatment. Placement of the ablation instrument 120 adjacent to the tissue of interest that requires treatment is performed by conventional methods (eg, over a guide wire under fluoroscopic guidance). When properly positioned, the expandable member 130 is expanded from a folded transport configuration to an expanded configuration, for example, by pressurizing fluid from about 2 to 10 atmospheres in the case of a balloon. Thereby, a some electrode is arrange | positioned or pressed with respect to the wall part of the blood vessel. A plurality of active electrodes are activated. Ablation energy passes from multiple active electrodes through target tissue (sympathetic nerves are ablated, regulated, or impacted) and returned through multiple outer electrodes in a bipolar structure, or a monopolar structure Is transmitted back through the common outer electrode. Following processing, the expandable member 130 is folded into a collapsed transport configuration for storage within the guide sheath or catheter 14 and subsequent retraction from the blood vessel or body passage.

  Materials that can be used for various elements of the ablation device 120 (and / or other devices disclosed herein) include those commonly associated with medical devices. For purposes of simplicity only, ablation instrument 120 is described below. However, this is not intended to be limited to the instruments and methods disclosed herein. The following applies to other similar tubular members and / or expandable members disclosed herein, and / or elements of tubular members and / or expandable members.

  Ablation instrument 120 and its various elements are formed from metals, alloys, polymers (some examples of which are given below), metal-polymer composites, ceramics, combinations thereof, or other suitable materials. Is done. Some examples of suitable polymers are sold by polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxymethylene (POM, eg DuPont). DELRTN®), polyether block ester, polyurethane (eg polyurethane 85A), polypropylene (PP), polyvinyl chloride (PVC), polyether ester (eg DSM Engineering Plastics) ARNITEL®), ether or ester based copolymers (eg, butylene / poly (alkylene ether) phthalates and / or other polyesters such as HYTREL® sold by DuPont). Terelastomer), polyamide (for example, DURETHAN (registered trademark) sold by Bayer and CRISTAMID (registered trademark) sold by Elf Atochem), elastomeric polyamide, block polyamide / ether, polyether block Amides (sold under PEBA, for example the trademark PEBAX®), ethylene vinyl acetate copolymer (EVA), silicone, polyethylene (PE), Marlex® high density polyethylene, Marlex® Low density polyethylene, linear low density polyethylene (for example, REXELL (registered trademark)), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polytrimethylene terephthalate Polyethylene naphthalate (PEN), polyetheretherketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide (PPO), polyparaphenylene terephthalamide ( For example, KEVLAR (registered trademark), polysulfone, nylon, nylon 12 (such as GRILAMID (registered trademark) sold by EMS American Grilon), perfluoro (propyl vinyl ether) (PFA), ethylene vinyl alcohol, polyolefin, polystyrene , Epoxy resin, polyvinylidene chloride (PVdC), poly (styrene-b-isobutylene-b-styrene) (eg SIBS and / or SIBS 50A), poly Including Boneto, ionomers, polymers having biocompatibility, other suitable materials, or mixtures, combinations, copolymers thereof, polymer / metal composites, and the like. In some embodiments, the sheath can be mixed with a liquid crystal polymer (LCP). For example, the mixture can contain up to about 6 percent LCP.

  Some examples of suitable metals and alloys include: stainless steels such as 304V, 304L, and 316LV stainless steel; mild steel; nickel-titanium alloys such as linear elastic and / or superelastic Nitinol; nickel-chromium-molybdenum alloys (eg, UNS: N06625 such as INCONEL (registered trademark) 625, UNS: N06022, such as HASTELLOY (registered trademark), C-22 (registered trademark), UNS: N10276 such as C276 (registered trademark), etc. Other nickel alloys such as HASTELLOY® alloys, etc., nickel copper alloys (eg UNS: N04400 such as MONEL® 400, NICKELVAC® 400, NICORROS® 400) Nickel-cobalt-chromium-molybdenum alloys (eg UNS: R30035 such as MP35N®), nickel-molybdenum alloys (eg UNS: N10665 such as HASTELLOY® ALLOY B2®), etc. Nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, other nickel-tungsten or tungsten alloys, etc .; cobalt-chromium alloys; cobalt-chromium- Molybdenum alloys (eg UNS: R30003 such as ELGILOY®, PHYNOX®); platinum-rich stainless steel; titanium; combinations thereof; or other suitable materials.

  As suggested here, nickel-titanium and nitinol alloy systems available on the market are the categories indicated as “linear elastic” or “non-superelastic”, which is the traditional shape memory and chemistry in chemistry. Similar to superelastic deformation, but exhibits clear and useful mechanical properties. Linear elastic and / or non-superelastic nitinol is a linear elastic and / or non-superelastic material that has a substantial “superelastic plateau” or “flag region” in its stress / load curve as superelastic nitinol exhibits. It is distinguished from superelastic nitinol in that nitinol does not show. Alternatively, in linear elastic and / or non-superelastic nitinol, when the recoverable load increases, the superelastic flats and / or flag regions seen in superelastic nitinol are substantially reduced until plastic deformation is initiated. Stress continues to increase in a linear relationship, or not necessarily in a complete linear relationship, or at least in a more linear relationship. Thus, for purposes of this disclosure, linear elastic and / or non-superelastic nitinol is also referred to as “substantially” linear elastic and / or non-superelastic nitinol.

  In certain cases, linear elastic and / or non-superelastic nitinol is loaded with up to about 2-5% linear elastic and / or non-superelastic nitinol, but remains substantially elastic (eg, plastic deformation Previously, superelastic nitinol is further distinguishable from superelastic nitinol in that it is loaded up to about 8% before plastic deformation. Both of these materials can be distinguished from other linear elastic materials such as stainless steel (which can be further distinguished on the basis of its plasticity), which are approximately 0.2 to 0.44 prior to plastic deformation. Receive only a percentage load.

  In some embodiments, the linear elastic and / or non-superelastic nickel-titanium alloy is any martensite detectable by differential scanning calorimetry (DSC) and dynamic metal thermal analysis (DMTA) analysis over a large temperature range. / Alloy that does not show austenite phase change. For example, in some embodiments, martensite detectable by DSC and DMTA analysis in a range of about −60 degrees Celsius (° C.) to about 120 ° C. in a nickel-titanium alloy with linear elasticity and / or non-superelasticity. / There is no austenite phase change. Thus, the mechanical bending properties of such materials are usually inactive with respect to temperature effects over this wide range of temperatures. In some embodiments, the mechanical bending properties of linear elastic and / or non-superelastic nickel-titanium alloys at ambient or room temperature are, for example, that they do not exhibit superelastic flats and / or flag regions. Is substantially the same as the mechanical characteristics at body temperature. That is, across a wide temperature range, a linear elastic and / or non-superelastic nickel-titanium alloy retains its linear elastic and / or non-superelastic characteristics and / or properties.

  In some embodiments, the linear elastic and / or non-superelastic nickel-titanium alloy is nickel in the range of about 50 to about 60 weight percent with the balance being substantially titanium. In some embodiments, the composition is a Nicke in the range of about 54 to about 57 weight percent. An example of a suitable nickel-titanium alloy is the FHP-NT alloy sold by Furukawa Techno Materials of Kanagawa (Japan). Some examples of nickel-titanium alloys are disclosed in US Pat. Nos. 5,234,004 and 6,508,803, which are hereby incorporated in their entirety. Other suitable materials include ULTINIUM® (sold by Neo-Metrics) and GUM METAL® (sold by Toyota). In some other embodiments, a superelastic alloy, such as a superelastic nitinol, is used to obtain the desired properties.

  In at least some embodiments, the portion of the ablation instrument 120 is further doped, formed or includes a radiopaque material. A radiopaque material can be one that can produce a relatively bright image on a fluoroscopic screen or another imaging technique during a medical procedure. This relatively bright image assists the user of the ablation instrument 120 to determine its location. Some examples of radiopaque materials include, but are not limited to, gold, platinum, palladium, tantalum, tungsten alloys, polymeric materials loaded with radiopaque fillers, and the like. In addition, other radiopaque marker bands and / or coils are further incorporated into the configuration of the ablation instrument 120 to achieve the same result.

  In some embodiments, a predetermined degree of magnetic resonance imaging (MRI) compatibility is imparted to the ablation instrument 120. For example, the portion of the instrument is formed of a material that does not substantially distort the image or form artifacts (ie, gaps in the image). Certain ferromagnets are not suitable, for example, because they form artifacts in the MRI image. In some of these, and in another example, the portion of the ablation instrument 120 is further formed from a material that the MRI machine can image. Some materials that exhibit these properties include, for example, tungsten, cobalt-chromium-molybdenum alloys (eg, UNS: R30003 such as ELGILOY®, PHYNOX®), nickel-cobalt-chromium-molybdenum alloys. (Eg, UNS: R30035 such as MP35N®), nitinol, and others.

  US Patent Application Publication No. 2013-0165926A1, filed January 25, 2013 as US Patent Application No. 13/750879, is hereby incorporated in its entirety.

  The disclosure is merely illustrative in many respects. Changes may be made in detail with respect to shapes, dimensions, and process configurations, particularly without departing from the scope of the present disclosure. This includes the use of any element of an example embodiment used in other embodiments, to an extent appropriate. The scope of the present invention is defined in the language set forth in the appended claims.

Claims (15)

A medical device for tissue ablation,
A catheter shaft;
An expandable balloon disposed on the catheter shaft and capable of changing between an unexpanded configuration and an expanded configuration;
A plurality of elongated electrode assemblies each configured as a flexible circuit, the plurality of electrode assemblies each including a plurality of electrodes disposed in at least first and second spaced apart arrangements, the plurality of electrodes The assembly is disposed on an outer surface of the balloon;
Each of the plurality of electrode assemblies includes one or more temperature sensors aligned with two or more of the electrodes in the array.   The medical device of claim 1, wherein the first array includes a plurality of active electrodes and the second array includes a plurality of outer electrodes.   3. A medical device according to claim 1 or 2, wherein each temperature sensor is located under the electrode.   3. A medical device according to claim 1 or 2, wherein each temperature sensor is located between two of the electrodes in the array.   The medical device according to any one of claims 2 to 4, wherein the outer electrode is disposed on a ground trace, and the one or more temperature sensors share the ground trace.   Each of the plurality of elongate electrode assemblies is formed of one or more laminated polymer / copper sheets, the outer electrode is formed in a recess of a polymer layer, and the one or more temperature sensors include two of the two or more temperature sensors. The medical device according to claim 4, wherein the medical device is disposed in a recess between the outer electrodes.   The one or more laminated polymer-copper sheets comprise two laminated sheets, each sheet comprising a polymer layer laminated to a copper layer, wherein the sheet comprises a second sheet polymer layer. The outer sheet is formed on the polymer layer of the first sheet, and the one or more temperature sensors are formed of the copper layer of the second sheet. The medical device according to claim 6, wherein a via is connected to the copper layer of the first and second sheets.   The one or more temperature sensors are disposed at the bottom of each of the plurality of electrode assemblies, and the bottom is attached to the outer surface of the balloon. The medical device according to Item.   The medical device according to any one of claims 1 to 8, wherein the plurality of electrode assemblies are configured to be unfolded and folded together with the balloon.   The medical device according to claim 9, wherein the balloon is a non-compliant balloon.   The plurality of elongate electrode assemblies includes a base layer extending under and between the plurality of electrodes, and a portion of the base layer between the first array and the second array The medical device according to claim 1, wherein the medical device is removed.   The medical device according to any one of claims 1 to 11, wherein the one or more temperature sensors are thermistors.   The medical device according to any one of claims 1 to 12, wherein the electrodes of the first and second arrays are arranged linearly.   14. A medical device according to any one of claims 2 to 13, wherein each temperature sensor is disposed proximal to the most proximal outer electrode on each electrode assembly.   15. The medical device according to any one of claims 1 to 11, 13, and 14, wherein each temperature sensor is a sputtered thermocouple.